AEM EMS Series II Decel function

[Valhalla]

So my system is running real well. No issues with the low RPM, very stock like. The transition to boost (at 2,500 rpm:biggrin is very smooth and at VTEC you had better be holding onto something. But tuning the EMS for drive-by-wire has not been real smooth. To get to have all the above stated goodness, we have had to compromise on decel. Let me explain.

The OEM ECU still controls the throttle and butterfly plate. As part of the emission control, that plate slowly closes and hangs at about 8% open for a short period of time. I have had two options. The first, we had the tune where the throttle would close immediately. But there was a stumble at low rpm's as I accelerated and also if you feathered the throttle, like in heavy traffic, the car was either in the gas or none at all and bucked like crazy. So we adjusted for tune 2.

Tun 2 is where we are now with all the goodness in the first paragraph. the problem is when you let off the gas, the throttle seems to hang at whatever rpm you were at for 4-5 seconds and then slowly goes down to idle with a slight dip below normal idle and then recovers to normal. It's not hard to drive, I'm just aware of it.

So my question is this, in EMS Series II, is there a decel function that can be activated to assist for DBW cars? Thanks in advance for any info.

 

[kookoo4nsx]

I wonder if this is a problem with ems2 on all factory drive by wire cars or just inherent to the NSX? Perhaps a quick call to AEM tech help?

So my system is running real well. No issues with the low RPM, very stock like. The transition to boost (at 2,500 rpm:biggrin is very smooth and at VTEC you had better be holding onto something. But tuning the EMS for drive-by-wire has not been real smooth. To get to have all the above stated goodness, we have had to compromise on decel. Let me explain.

The OEM ECU still controls the throttle and butterfly plate. As part of the emission control, that plate slowly closes and hangs at about 8% open for a short period of time. I have had two options. The first, we had the tune where the throttle would close immediately. But there was a stumble at low rpm's as I accelerated and also if you feathered the throttle, like in heavy traffic, the car was either in the gas or none at all and bucked like crazy. So we adjusted for tune 2.

Tun 2 is where we are now with all the goodness in the first paragraph. the problem is when you let off the gas, the throttle seems to hang at whatever rpm you were at for 4-5 seconds and then slowly goes down to idle with a slight dip below normal idle and then recovers to normal. It's not hard to drive, I'm just aware of it.

So my question is this, in EMS Series II, is there a decel function that can be activated to assist for DBW cars? Thanks in advance for any info.

 

[ScienceofSpeed]

Do you have this?
http://scienceofspeed.com/products/engine_performance_products/NSX/ScienceofSpeed/EMS_1995-2005_NSX/

The decel strategy is worked out in the base calibration we provide. Did you start with this, something else, or another brand?

-- Chris

 

[Valhalla]

Chris, thanks for chiming in. Email sent.

Yes that is the package. AEM EMS Series II with Boomslang harness and UEGO widebands. Works real nice except for the decel which is just more of an annoyance than anything. It's like I'm heel-toe driving all the time.